Concrete blocks are utilised to build property foundations and walls, and there are several tips on how to insulate them. If the cores aren’t stuffed with steel and concrete for structural reasons, they can be stuffed with insulation, which raises the common wall R-benefit. You can even pay for insulation https://freeecogrants.co.uk/what-are-the-steps-to-apply-for-free-external-wall-insulation/